Ice adhesion on polysaccharide materials from psychrophilic bacteria

Exopolysaccharides (EPS) are carbohydrate biopolymers produced by microorganisms and secreted into their environment to aid survival. EPS from psychrophilic bacteria (bacteria that adapted to living below zero) were found to counteract various environmental stresses associated with freezing temperatures. Together with AFP, EPS production is an alternative strategy for survival in hostile conditions of subzero temperatures. Given the great structural complexity of EPS, only a few EPS from psychrophilic bacteria with cryoprotective properties were fully characterized. A notable example is Colwellia psychrerythraea 34H, which has been previously shown to produce two types of EPS with cryoprotective properties [1]. These findings open intriguing opportunities to develop materials based on Colwellia psychrerythraea 34H EPS for exploring the potential of low ice adhesion materials with applications in energy systems and aeronautics. In our work, we successfully cultured Colwellia psychrerythraea 34H using two different cultivation techniques (batch and bioreactor methods). The EPS were then isolated through subsequent separation processes. EPS were deposited as monolayers onto glass slides but also incorporated into agar-based hydrogels (figure 1). These materials were assessed for their icephobic characteristics, particularly focusing on their capacity to reduce ice adhesion. Although the de-icing performance still requires refinement, the results of this study present a promising new approach to developing biotechnological materials with icephobic properties.